To provide the greatest compatibility between software and hardware components on a computer system, the operating system of the computer defines certain interfaces which can be accessed and used by the programmers of the software components and which are to be provided and supported by the designers of hardware components. Thus, by using the defined interface, the software component can be assured of compatibility with all of the hardware components which support the interface. Similarly, a hardware component providing a specific interface can be assured that software components will be able to locate and access the functionality provided by the hardware component through the interface.
Generally, computers and other electronic devices are interconnected via physical cables or wires. These communication paths allow for the exchange of data or control information between such devices. However, it is increasingly recognized that certain advantages arise from the elimination of cables and wires to interconnect devices. Such advantages include ease of configuration and reconfiguration, due to the elimination of the need to physically add, remove, or displace a physical medium. Furthermore, space which would traditionally be used for device interconnection media may be given to other uses. Furthermore, device mobility is increased through the use of wireless connections.
One method for providing wireless connections between devices employs a light wave in the Infrared region of the electromagnetic spectrum to link devices. The IrDA (Infrared Data Association) protocol defines one such connection mechanism. Unfortunately, such a mechanism must usually operate in a line of sight manner. That is to say that any opaque obstruction between transmitter and receiver will prevent proper operation. Additionally, IR transmitters are typically not omnidirectional when incorporated into a communicating device, so that for proper operation, the transmitter must be pointed generally in the direction of the receiver, within some nominal deviation such as 30 degrees. Finally, IR transmitters are typically fairly low power devices, and accordingly the range of IR links is usually limited to approximately one meter.
Radio frequency links solve many of the problems inherent in Infrared links, however, a radio frequency connection scheme is needed whereby a variety of applications can easily access the radio link through a connection mechanism that provides an appropriate interface. One protocol which defines communication between wireless devices through radio frequency links is the Bluetooth specification. Bluetooth devices do not require a line of sight with one another to operate, and their range can be significantly greater than that of IR links. However, one difficulty with the Bluetooth specification is that very few computer software programs are written to communicate with Bluetooth compliant devices. Another difficulty with the Bluetooth specification is that Bluetooth compliant devices are presented to computer software programs as serial interfaces. There are be numerous situations it which such a serial presentation can be inefficient or even confusing for certain types of computer software applications, such as simple networking applications. Yet another difficulty with the Bluetooth specification is that, while it supports up to 30 emulated RS-232 ports, computer software programs are generally required to know how to communicate through such an emulated port in a device-specific manner.